Accurate characterization of the physical properties of atmospheric hydrometeors is useful for a broad range of practical and scientific applications. For example, hydrometeor diameter, mass, and fall-speed relationships are useful components of weather and climate numerical models used in forecasting. The range of possible particle shapes and sizes is extremely broad, and includes raindrops, dendritic snowflakes, aggregated forms, graupel, hail, etc. with numerous potential variations, and generally includes sizes ranging in diameters from less than a millimeter to several centimeters.
A wide variety of electro-optical and communications devices and methods have been developed for inspecting and analyzing hydrometeors. Such systems have attempted to characterize hydrometeor structures and relate crystalline forms to changes in atmospheric electromagnetic attenuation, fall velocity, density, etc. These systems often utilize lasers, shadows and diffraction patterns to classify hydrometeors. Further, viewing of hydrometeors generally may take place in the field. However, such devices configured for viewing hydrometeors in the field have often involved significant manual intervention and have been unpredictable and/or unreliable, especially at temperatures near freezing. In addition, past devices have not provided sufficient visualization of the more minute features of hydrometeors, such as the crystalline structure of snowflakes or ice, in a continuous fashion or in an accurate manner.
The ability to accurately and dependably study various particles in the field, including hydrometeors, can be useful in a variety of applications. For example, departments of transportation may use information developed from the analysis of hydrometeors to better respond to weather conditions that may be affecting public roads. Being able to document and image hydrometeors and properties of the hydrometeors, particularly at close range, is potentially useful for a wide variety of applications. For example, improvements in systems can be useful for documenting and imaging hydrometeors, as well as for providing information on the oscillation of hydrometeors, the conditions at which the hydrometeors tumble, the specific type of crystals that traverse a point along a line of sight, and the relationship between fall speed and particle size, color data, volume data, fall speed, and trajectory.